Copperhead

I’ve been experiencing the infamous long crank starting problem since buying my Jeep a few months ago…Testing revealed a drop in pressure at shutdown isolated to the rail system and not the fuel line…The starting problem had been occurring whether the vehicle has been sitting for days or for 15 minutes…

The only strange change to it’s behavior is that since the temperatures in my area have cooled considerably recently, I find that the engine will start IMMEDIATELY(1 -2 cranks) after sitting overnight…after warm-up it returns to it’s old annoying self…

Although there are no visible leaks…I do get a smell of fuel at startup…I’m assuming the problem lies with the injectors and plan to clean them and replace the o-rings…

But I am curious as to why a drop in air temperature would eliminate the hard start totally….Can anyone who has a better understanding of injectors offer an explanation for this?…Or is there something else that I may be overlooking? ….Also, while it runs fine...at idle… the tach will "jiggle" up and down about 200 rpm in either direction….Thanks

daniele70

Well I can say that I know how it feels to have a problem and not know what direction to go in.
The crank sensor and the cam sensor are used by the PCM to determine when to fire the injectors and cylinders. It also uses them to give you a tach signal. Hard start when its warmer outside means less resistance on electronic devices. When it is colder then you have a high resistance. Anyways. you can check the crank and cam sensor with the help of a friend. Go to autozone and buy the hayes manual for $20. Comes in real handy.

Good luck.

steve_k_37801

i also own a 2001 sport and experience the start up issues the same as you. When it cold no problems starting but when its warm 7-10 seconds on start up. Did you ever find anything out on yours. Just posted a thread to see if i could find any thing out. Thanks Steve